How to transform a PDDL to search?
Not all search is planning (is A connected to B), but all planning is search (how do I get from this to that). 

Here's an example in Prolog with a domain described in terms of actions, when they are possible, and what the result of the actions are. The description is of an uncomputed graph of un-calculated size where each node is a situation and each edge is an action. Then we have A* search algorithm that searches this graph, calculating it as it goes, to find a plan to reach the goal state. Running the final query will produce a plan via search.